• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 62 subscribers
  • Views 185 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ40Z60: Do we need to update QMAX frequently?

Widji Santoso
Prodigy 90 points
Part Number: BQ40Z60

Hi,

In our current application, We don't have much time to let the system to get valid OCV reading because the system has to be ready whenever it needed. Once the battery already got one regular QMAX update (not from fast QMAX), my question is:

  1. Do we still need to update QMAX frequently?
  2. Is there anything that can cause the QMAX to change so we need to update the QMAX frequently?

Thanks for your help

  • 0
    TI__Guru 57747 points

    QMAX changes due to battery degradation/ageing. If you have done the initial QMAX learning, then the gauge will report accurately at that time. If QMAX subsequently changes and the gauge does not get valid OCV readings, then the gauge wlll still report based on old QMAX. This can result in higher errors and affects accuracy.

  • 0 in reply to Shirish
    Prodigy 90 points

    Do you have best practice how often we should update the QMAX based on our case? because our device maybe not able to reach VCT frequently doe to our use case.

  • 0 in reply to Widji Santoso
    TI__Guru 57747 points

    Hello Widji,

    It is recommended to have at least one rest for OCV readings in every cycle. In a temperature controlled environment the degradation is gradual and therefore QMAX changes slowly. If the pack is exposed to conditions that cause quicker changes in QMAX, then not getting OCV readings for a few cycles will be a concern for accuracy.